Apparatus for straightening discs



April 10, 1962 o. A. KERSHNER ETAL, 3,028,906

APPARATUS FOR STRAIGHTENING DISCS Filed July 6, 1959 2 Sheets-Sheet 1INVENTORS April 10, 1962 o. A. KERSHNER ETAL 350235906 1 APPARATUS FORSTRAIGHTENING nxscs Filed July 6, 1959 2 Sheets-Sheet 2 INVENTORS FiledJuly 6, 1959, Ser. No. $25,257 4 Ciaims. (Cl. 153-102) The presentinvention relates to a novel apparatus for producing flat sheet metalarticles, and more particularly to a novel apparatus for producing fiatsheet metal discs.

While it will become apparent that various articles may be produced byutilizing the apparatus of the present invention, the present disclosurewill be expedited by describing the apparatus as applied to theproduction of sheet metal annular discs to be used in disc type brakesof the class disclosed in US. Patent 2,387,039. Such discs are usuallystamped from wide sheets of stock material which is substantially flat,but apparently as a result of internal stresses, the stamped discs areusually warped to such an extent that they must be straightened beforethey can be used in a brake assembly. Heretofore the discs have beenstraightened by hand hammering but this procedure requires theexpenditure of considerable amounts of skilled labor so that it isexpensive and unsatisfactory. It has also been previously suggested thatsuch discs may be straightened by compressing them with great forcebetween opposing dies having annular ribs thereon, but such a procedureforms annular grooves in the opposite sides of the discs, which groovesraise additional problems in securing brake lining material thereto.

It is an important object ofthe present invention to provide a novelapparatus for straightening Warped or deformed sheet material discsaccurately and economically.

A further object of the present invention is to provide a novelapparatus for straightening warped or deformed sheet material discs in amanner so that the finished discs have a substantially smooth surface.

Still another object of the present invention is to provide a novelapparatus for straightening discs in the manner described above, whichapparatus is of simple, rugged and efficient construction.

Other objects and advantages of the present invention will becomeapparent from the following description and the accompanying drawingswherein:

FIG. 1 is a simplified view partially in cross section showing anapparatus incorporating features of the present invention;

FIG. 2 is a perspective view showing a disc of the type to bestraightened in accordance with the present invention;

FIG. 3 is an edge view showing a warped disc of the States Patent typeto be straightened in accordance with the present invention;

FIG. 4 is an exploded perspective view showing a portion of theapparatus of the present invention;

FIG. 5 is an exploded perspective view showing another portion of theapparatus adapted to be assembled in opposition to the portion shown inFIG. 4;

FIG. 6 is a perspective view showing an element of the apparatus;

FIG. 7 is an enlarged fragmentary partial sectional view taken alongline 77 in FIG. 1; and

FIG. 8 is a sectional view taken generally along line 8-8 in FIG. 7.

Referring more specifically to the drawings wherein like parts aredesignated by the same numerals throughout the various figures, anapparatus 10 incorporating ice features of the present invention isshown in simplified form in FIG. 1. The apparatus comprises a fixture 12including opposing sections 14 and 16 respectively fixed on and carriedby a driven shaft 13 and a ram 20. Any suitable means such as anelectric motor 22 may be provided for driving the shaft 18 throughsuitable reduction gearing 24. The ram extends into and is actuated by ahydraulic cylinder 26 for clamping a disc to be straightened between thetwo halves 14 and 16 of the fixture 12 in the manner described in detailbelow.

A sheet metal disc 28 of the type to be straightened in accordance withthe present invention is shown in FIGS. 2, 3, 7 and 8. When the disc isto be used as a part of a brake assembly, annular washers 30 and 32having splined inner margins are welded to the opposite sides of theannular disc.

In accordance with the present invention, a disc 28 to be straightenedis clamped between the opposing halves 14 and 16 of the fixture 12whereupon the fixture and the disc are rotated relative to each other.The fixture is constructed in the manner described in detail below sothat during such relative rotation each circumferentially extendingsegment of the disc is repeatedly deformed back and forth beyond theelastic limit of the material. It has been found that as a result ofthis method of processing the disc, a warped disc will be substantiallystraightened or flattened. In fact, it has been found that, by way ofexample, discs may consistently be flattened to within a tolerance of0.005 inch.

Referring specifically to FIGS. 1, 6 and 7, it is seen that the section14 of the fixture or unit 12 comprises a main body member 34 whichextends radially from a central hub 36 adapted to be fixed to the shaft18. An annular rearwardly inclined or frusto-conical seat 38 is formedin an end face 40 of the body member 34 to provide a hearing or back upsurface for a pluralityof rollers 42 which are adapted to engage andwork the disc '23 in the manner described below. 'As shown best in FIG.7, each of the rollers 42 is tapered or fl'l StO1 conical inconfiguration and the angle of inclination of the bearing surface 38 tothe rotative axis of the body member 34 and the included angle of thetaper of the rollers 42 are correlated so that the sides of the rollersopposite from the bearing surface 38 are tangent to a common plane whichis perpendicular to the rota tive axis of the body member 34. Thus therollers 42 are adapted to engage a properly positioned disc 28 with linecontact substantially throughout their entire lengths.

In the embodiment illustrated, four rollers 42' are provided, whichrollers are equally spaced around the bearing surface 38. In order toretain the rollers in the desired relative positions, a cage member orplate '44 is provided for overlying the rollers. Equally spaced taperedslots 46 are provided around the cage member 44 for exposing portions ofthe rollers which project therethrough. Of course, the width of theslots is less than the diameter of the rollers so that the'rollerscannot pass entirely through the slots. In order to absorb generallyradially outwardly directed thrust loads, the body member 34 isprovidedwith a second annular bearing surface 48 flaring outwardly from ajunction with the surface.

38 and being slightly curved or dished for accommodating rounded endsurfaces 50 of the rollers. The cage member 44 is provided with acentral hub portion 52 mounted on a stub shaft 54 projecting axiallyfrom the body member 34. A snap ring 56 or the like is assembled overthe end of the stub shaft 54 for retaining the cage member thereon.

The section 16 of the fixture unit 12 comprises a body member 58 similarto the body member 34 and radiating from a central hub portion 60. Asshown in FIG. 7,

the hub portion 60 is mounted on an end portion ofthe' 3 ram by radialand thrust bearing units 62 and 64 respectively so that the body member58 is adapted to rotate relative to the ram 20. The ram 20 is fixedagainst rotation and this may be accomplished by various suitable meanssuch as a key 66 fixed with respect to the cylinder 26 and projectinginto an elongated slot 68 in the ram (see FIG. 1).

The body member 58 is provided with bearing surfaces 70 and 72 which arerespectively identical to the surfaces 38 and 48 described above andwhich are adapted to accommodate a plurality of rollers 74 which areidentical to the rollers 42. The rollers 74 are retained in equallyspaced relationship around the body member 58 by means of a cage member76 which is shown best in FIGS. 4, 7 and 8. The cage member 76 issimilar to the above described cage member 44 and comprises a pluralityof tapered slots 78 through which portions of the rollers 74 project. Acentral hub portion 80 is formed on the cage member 76 for mounting thecage member on a reduced diameter portion 82 of the ram 20. A suitableretaining ring 84 is provided on the ram for retaining the cage member76.

In the embodiment illustrated herein, the disc 28 is mounted between thesections 14 and 16 and fixed against rotation during a straighteningoperation. This is accomplished by providing a ring 86 having peripheralsplines adapted to accommodate the splined washers 30 and 32 which aresecured to the opposite sides of the disc 28 so that the disc is fixedagainst rotation relative to the ring. The ring 86 is in turnnon-rotatably supported on the rectangular or non-circular reduceddiameter end portion 88 of the ram 20 as shown in FIGS. 7 and 8.

As indicated above, the body member 34 is driven by the shaft 18. Meansis provided for driving the body member 53 from the body member 34during a workpiece straightening operation. This means comprises aplurality of fingers 90 equally spaced around and formed integrally withthe periphery of the body member 34 and projecting toward the bodymember 58 for interengagement with similar fingers 92 projecting fromthe body member 58. It will be appreciated that this arrangement enablesthe body members 34 and 58 to be spread apart for enabling a disc to beinserted therebetween and remove therefrom without taking any specialaction to either connect or disconnect the driving means between thebody members.

As indicated in FIGS. 7 and 8, the cage members 44 and 76 are locatedwith respect to each other during a workpiece straightening operation sothat the rollers 44 are angularly offset from or disposed between therollers 74. Thus when the ram 26 is actuated by the hydraulic cylinderso as to advance the section 16 toward the section 14 and therebyaggressively clamp the disc 28 between the annular series of rollers 42and 74, successive rollers 42 and 74 cause successive segments of thedisc to be deflected in opposite directions from a central plane. Thenupon rotation of the unit 12 relative to the disc, the deflections orundulations in the disc 28 are progressively and repeatedly reversed toaccomplish the straightening of the disc described above. In order toposition the cage members and their associated rollers with respect toeach other, fingers 94 are equally spaced around the periphery of thecage member 76 and extend axially for entry between pairs of fingers 96provided on and extending from the periphery of the cage member 44.

While the method of straightening a disc member with the apparatusof thepresent invention is believed to be clear from the description above, abrief rsurn of the procedure is as follows. The hydraulic cylinder 26which is connected with a suitable source of hydraulic fluid underpressure, not shown, is first actuated so as to retract the ram 20 andthereby the section 16 of the unit 12 from the section 14. Then a discto be straightened is mounted on the splined ring 86 and the cylinder 26is actuated to advance the section 16 toward the section 14 and clampthe disc between the sets of rollers. As the section of the unit 12advances, the fingers 94 enter between the fingers 96 to loclc the cagemembers with respect to each other and the fingers project forinterengagement with the fingers 92. Then when the pressure in thecylinder 26 has built up so that the disc is clamped between the rollerswith a predetermined force, which for example, may be about fivethousand pounds, a pressure responsive switch 100 (FIG. 1) connectedwith the cylinder 26 is actuated for energizing a suitable relay 192 forstarting the motor 22. Upon rotation of the body members 34 and 58, thesets of rollers are frictionally driven around the disc 28 forrepeatedly flexing and thereby straightening the disc in the mannerdescribed above. It has been found that the straightening operation canbe accomplished very quickly and by way of example only it has beenfound that rotation of the unit 12 at about 300 rpm. for a period of 5or 6 seconds will usually be sufiicient to accomplish the desiredstraightening of a workpiece.

While the preferred embodiment of the present invention has been shownand described herein, it is obvious that many structural details may bechanged without departing from the spirit and scope of the appendedclaims. For example, the apparatus described herein may readily bemodified so that the disc is rotated while the fixture or unit 12 isfixed against rotation during a straightening operation.

The invention is claimed as follows:

1. An apparatus of the type described for straightening a disccomprising means for supporting a disc to be straightened on andperpendicular to a predetermined axis, means engageable with a supporteddisc for ondulating the disc, said last named means including taperedrollers extending generally radially with respect to said axis andangularly ofiset from each other and disposed with their respective axesinclined with respect to said predetermined axis and with sides thereoftangent to planes perpendicular to said prcdetermined'axis andengageable with opposite sides of the disc, a first body memberincluding a frusto-conical bearing surface sup porting one of saidrollers engageable with one side of said disc, a second body memberincluding another frustoconical bearing surface supporting another ofsaid rollers engageable with an opposite side of the disc, first andsecond cage members respectively assembled in association with andrelatively rotatable with respect to said first and second body membersfor retaining said rollers respectively in association with said firstand second body members, each of said cage members extending in a planegenerally perpendicular to said predetermined axis and having taperedopening means therein through which a portion of a roller associatedtherewith projects for engagement with the disc, and said cage membersincluding cooperable axially interengageable means for releasablylocking the cage members in predetermined relationship with respect toeach other.

2. An apparatus of the type described for straightening discs comprisingmeans for supporting a disc on and perpendicular to a predeterminedaxis, a first body member axially aligned with said axis, a second bodymember axially aligned with said axis, a first series of annularlyspaced rollers assembled with and bearing against said first body memberand having sides opposite from said first body member tangent to a planedisposed perpendicular to said axis for engaging one side of the disc, asecond series of annularly spaced rollers assembled with and bearingagainst said second body member and having sides opposite from saidsecond body member substantially tangent to a plane perpendicular tosaid axis for engaging a side of the disc opposite from said firstmentioned rollers, the rollers in said first series being angularlyoffset from the rollers in said second series for undulating the discwhen the disc is clamped between the two series of rollers, said rollersbeing tapered, said body members including first frusto-conical bearingsurfaces engageable with sides of said rollers and second annularbearing surfaces projecting from adjacent outer margins of said firstsurfaces and engaging generally radially outer ends of the rollers,first and second cage members respectively assembled in association withand relatively rotatable with respect to said first and second bodymembers for retaining said first and second series of rollers, said cagemembers having opening means therein through which portions of therollers associated therewith project for engagement with a disc, andcooperable means on said first and second cage members for releasablylocking the cage members in predetermined relationship with respect toeach other.

3. An apparatus, as defined in claim 2, which includes means foradvancing and retracting said body members with respect to each otherfor clamping and releasing a disc therebetween, and means for relativelyrotating said body members and said disc supporting means for relativelyadvancing said rollers around the disc.

4. An apparatus, as defined in claim 3, which includes fluid pressuremeans for relatively advancing said body members with respect to eachother for clamping the disc, motor means for rotating the body memberswhen the disc is clamped, and pressure sensitive switch means associatedwith said fluid pressure means for energizing said motor after a disc isclamped with a predetermined pressure.

References Cited in the file of this patent UNITED STATES PATENTS698,351 Arnold Apr. 22, 1902 1,601,795 Glover Oct. 5, 1926 1,672,208Glover June 5, 1928 2,398,227 Hubbert Apr. 9, 1946 2,724,625 White Nov.22, 1955

